• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6457-6461
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• 2015

MicroRNAs directly and indirectly influence many biological processes such as apoptosis, cell maintenance, and immune responses, impacting on tumor genesis and metastasis. They modulate gene expression at the posttranscriptional level and are associated with progression of liver disease. Hepatocellular carcinoma (HCC) is a cancer which mostly occurs in males. There are many factors affect HCC development, for example, hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV), co-infection, environmental factors including alcohol, aflatoxin consumption and host-related factors such as age, gender immune response, microRNA and single nucleotide polymorphisms (SNPs). Chronic infection with the hepatitis B virus is the major factor leading to HCC progression since it causes the liver injury. At present, there are many reports regarding the association of SNPs on miRNAs and the HCC progression. In this research, we investigated the role of miR-149 (rs2292832) and miR-101-1 (rs7536540) with HCC progression in Thai population. The study included 289 Thai subjects including 104 HCC patients, 90 patients with chronic hepatitis B virus infection (CHB) and 95 healthy control subjects. The allele and genotype of rs2292832 and rs7536540 polymorphisms were determined by TaqMan real-time PCR assay. Our results revealed no significant association between miR-149 (rs2292832) and miR-101-1 (rs7536540) and the risk of HCC in our Thai population. However, this research is the first study of miR-149 (rs2292832) and miR-101-1 (rs7536540) in HCC in Thai populations and the results need to be confirmed with a larger population.

• Genomics & Informatics
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• v.19 no.2
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• pp.17.1-17.13
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• 2021

Breast cancer is one of the leading causes of cancer in women all over the world and accounts for ~25% of newly observed cancers in women. Epigenetic modifications influence differential expression of genes through non-coding RNA and play a crucial role in cancer regulation. In the present study, epigenetic regulation of gene expression by in-silico analysis of histone modifications using chromatin immunoprecipitation sequencing (ChIP-Seq) has been carried out. Histone modification data of H3K4me3 from one normal-like and four breast cancer cell lines were used to predict miRNA expression at the promoter level. Predicted miRNA promoters (based on ChIP-Seq) were used as a probe to identify gene targets. Five triple-negative breast cancer (TNBC)-specific miRNAs (miR153-1, miR4767, miR4487, miR6720, and miR-LET7I) were identified and corresponding 13 gene targets were predicted. Eight miRNA promoter peaks were predicted to be differentially expressed in at least three breast cancer cell lines (miR4512, miR6791, miR330, miR3180-3, miR6080, miR5787, miR6733, and miR3613). A total of 44 gene targets were identified based on the 3'-untranslated regions of downregulated mRNA genes that contain putative binding targets to these eight miRNAs. These include 17 and 15 genes in luminal-A type and TNBC respectively, that have been reported to be associated with breast cancer regulation. Of the remaining 12 genes, seven (A4GALT, C2ORF74, HRCT1, ZC4H2, ZNF512, ZNF655, and ZNF608) show similar relative expression profiles in large patient samples and other breast cancer cell lines thereby giving insight into predicted role of H3K4me3 mediated gene regulation via the miRNA-mRNA axis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1675-1679
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• 2014

Objectives: MicroRNAs (miRNAs) are important regulators of many physiological and pathological processes, including tumorigenesis and metastasis. In this study, we sought to determine the underlying molecular mechanisms of metastatic cervical carcinoma by performing miRNA profiling. Methods: Tissue samples were collected from ten cervical squamous cancer patients who underwent hysterectomy and pelvic lymph node (PLN) dissection in our hospital, including four PLN-positive (metastatic) cases and six PLN-negative (non-metastatic) cases. A miRNA microarray platform with 1223 probes was used to determine the miRNA expression profiles of these two tissue types and case groups. MiRNAs having at least 4-fold differential expression between PLN-positive and PLN-negative cervical cancer tissues were bioinformatically analyzed for target gene prediction. MiRNAs with tumor-associated target genes were validated by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Results: Thirty-nine miRNAs were differentially expressed (>4-fold) between the PLN-positive and PLN-negative groups, of which, 22 were up-regulated and 17 were down-regulated. Sixty-nine percent of the miRNAs (27/39) had tumor-associated target genes, and the expression levels of six of those (miR-126, miR-96, miR-144, miR-657, miR-490-5p, and miR-323-3p) were confirmed by quantitative (q)RT-PCR. Conclusions: Six MiRNAs with predicted tumor-associated target genes encoding proteins that are known to be involved in cell adhesion, cytoskeletal remodeling, cell proliferation, cell migration, and apoptosis were identified. These findings suggest that a panel of miRNAs may regulate multiple and various steps of the metastasis cascade by targeting metastasis-associated genes. Since these six miRNAs are predicted to target tumor-associated genes, it is likely that they contribute to the metastatic potential of cervical cancer and may aid in prognosis or molecular therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9523-9527
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• 2014

The incidence of colorectal cancer (CRC) is increasing in many Asian countries and microRNAs have already been proven to be associated with tumorigenesis. Currently, microRNA-376a (miR-376a) expression and association with clinical factors in CRC remains unclear. In this study, real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was carried out on 53 matched pairs of CRC and adjacent normal mucosa to investigate the expression levels of miR-376a. According to the high or low expression of miR-376a, patients were divided into two groups. The relationship between miR-376a expression and clinicopathological factors of 53 patients was evaluated. Survival analysis of 53 CRC patients was performed with clinical follow-up information and survival curves were assessed by the Kaplan-Meier method. Immunohistochemistry (IHC) staining was performed on sections of paraffin-embedded tissue to investigate the vascular endothelial growth factor (VEGF) expression. MiR-376a showed low expression in cancer tissues compared to the adjacent normal tissues and altered high miR-376a expression tended to be positively correlated with advanced lymph node metastasis and shorter patient survival. VEGF IHC positivity was significantly more common in patients with high expression levels of miR-376a.Those results demonstrated that miR-376a may be a meaningful prognostic biomarker and potential therapeutic target in colorectal cancer.

• Genomics & Informatics
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• v.15 no.3
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• pp.98-107
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• 2017

MicroRNAs (miRNAs) act as regulators of gene expression by binding to the 3' untranslated region (UTR) of target genes. They perform important biological functions in the various species. Among many miRNAs, miR-21-3p is known to serve vital functions in development and apoptosis in olive flounder. Using genomic and bioinformatic tools, evolutionary conservation of miR-21-3p was examined in various species, and expression pattern was analyzed in olive flounder. Conserved sequences (5'-CAGUCG-3') in numerous species were detected through the stem-loop structure of miR-21-3p. Thus, we analyzed target genes of miR-21-3p. Among them, 3' UTR region of PPIL2 gene indicated the highest binding affinity with miR-21-3p based on the minimum free energy value. The PPIL2 gene showed high expression levels in testis tissue of the olive flounder, whereas miR-21-3p showed rather ubiquitous expression patterns except in testis tissue, indicating that miR-21-3p seems to control the PPIL2 gene expression in a complementary repression manner in various tissues of olive flounder. Taken together, this current study contributes to infer the target gene candidates for the miR-21-3p using bioinformatics tools. Furthermore, our data offers important information on the relationship between miR-21-3p and target gene for further functional study.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4969-4976
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• 2014

Background: miR-152 is involved in the genesis and development of several malignancies. However, its role in HCC has not been fully clarified. The aim of this study was to investigate the clinicopathological significance of miR-152 and its effect on the malignant phenotype of HCC cells. Methods: miR-152 expression was detected using real-time quantitative RT-PCR in 89 pairs of HCC formalin-fixed paraffin-embedded and their adjacent tissues. Functionally, in vitro effects and mechanisms of action of miR-152 on proliferation, viability, caspase activity, apoptosis and motility were explored in HepG2, HepB3 and SNU449 cells, as assessed by spectrophotometry, fluorimetry, fluorescence microscopy, wound-healing and Western blotting, respectively. Results: miR-152 expression in HCC was downregulated remarkably compared to that in adjacent hepatic tissues. miR-152 levels in groups of advanced clinical stage, larger tumor size and positive HBV infection, were significantly lower than in other groups. A miR-152 mimic could suppress cell growth, inhibit cell motility and increase caspase activity and apoptosis in HCC cell lines. Furthermore, Western blotting showed that the miR-152 mimic downregulated Wnt-1, DNMT1, ERK1/2, AKT and TNFRS6B signaling. Intriguingly, inverse correlation of TNFRF6B and miR-152 expression was found in HCC and bioinformatics confirmed that TNFRF6B might be a target of miR-152. Conclusions: Underexpression of miR-152 plays a vital role in hepatocarcinogenesis and lack of miR-152 is related to the progression of HCC through deregulation of cell proliferation, motility and apoptosis. miR-152 may act as a tumor suppressor miRNA by also targeting TNFRSF6B and is therefore a potential candidate biomarker for HCC diagnosis, prognosis and molecular therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1047-1055
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• 2014

Background: MicroRNAs (miRNAs) are an abundant class of endogenous small non-coding RNAs of 20-25 nucleotides in length that function as negative gene regulators. MiRNAs play roles in most biological processes, as well as diverse human diseases including cancer. Recently, many studies investigated the association between SNPs in miR-146a rs2910164, miR-196a2 rs11614913, miR-149 rs229283, miR-499 rs3746444 and colorectal cancer (CRC), which results have been inconclusive. Methodology/Principal Findings: PubMed, EMBASE, CNKI databases were searched with the last search updated on November 5, 2013. For miR-196a2 rs11614913, a significantly decreased risk of CRC development was observed under three genetic models (dominant model: OR = 0.848, 95%CI: 0.735-0.979, P = 0.025; recessive model: OR = 0.838, 95%CI: 0.721-0.974, P = 0.021; homozygous model: OR = 0.754, 95%CI: 0.627-0.907, P = 0.003). In the subgroup analyses, miR-$196a2^*T$ variant was associated with a significantly decreased susceptibility of CRC (allele model: OR = 0.839, 95%CI: 0.749-0.940, P = 0.000; dominant model: OR = 0.770, 95%CI: 0.653-0.980, P = 0.002; recessive model: OR = 0.802, 95%CI: 0.685-0.939, P = 0.006; homozygous model: OR = 0.695, 95%CI: 0.570-0.847, P = 0.000). As for miR-149 rs2292832, the two genetic models (recessive model: OR = 1.199, 95% CI 1.028-1.398, P = 0.021; heterozygous model: OR = 1.226, 95% CI 1.039-1.447, P = 0.013) demonstrated increased susceptibility to CRC. On subgroup analysis, significantly increased susceptibility of CRC was found in the genetic models (recessive model: OR = 1.180, 95% CI 1.008-1.382, P = 0.040; heterozygous model: OR = 1.202, 95% CI 1.013-1.425, P = 0.013) in the Asian group. Conclusions: These findings supported that the miR-196a2 rs11614913 and miR-149 rs2292832 polymorphisms may contribute to susceptibility to CRC.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9059-9064
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• 2014

MicroRNAs (miRNAs) are ubiquitously expressed small, non-coding RNAs that negatively regulate gene expression at a post transcriptional/translational level. They have emerging as playing crucial roles in cancer at all stages ranging from initiation to metastasis. As a tumor suppressor miRNA, aberrant expression of microRNA-29b (miR-29b) has been detected in various types of cancer, and its disturbance is related with tumor development and progression. In this review, we summarize the latest findings with regard to the tumor suppressor signatureof miR-29b and its regulatory mechanisms. Our review highlights the diverse relationships between miR-29b and its target genes in malignant tumors.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7575-7581
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• 2014

MicroRNAs (miRNAs) play an essential role in the development and progression of nasopharyngeal carcinomas (NPC). Despite advances in the field of cancer molecular biology and biomarker discovery, the development of clinically validated biomarkers for primary NPC has remained elusive. In this study, we investigated the expression and clinical significance of miRNAs as novel primary NPC diagnostic biomarkers. We used an array containing 2, 500 miRNAs to identify 22 significant miRNAs, and these candidate miRNAs were validated using 67 fresh NPC and 25 normal control tissues via quantitative real-time PCR (qRT-PCR). Expression and correlation analyses were performed with various statistical approaches, in addition to logistic regression and receiver operating characteristic curve analyses to evaluate diagnostic efficacy. qRT-PCR revealed five differentially expressed miRNAs (miR-93-5p, miR-135b-5p, miR-205-5p and miR-183-5p) in NPC tissue samples relative to control samples (p<0.05), with miR-135b-5p and miR-205-5p being of significant diagnostic value (p<0.01). Moreover, comparison of NPC patient clinicopathologic data revealed a negative correlation between miR-93-5p and miR-183-5p expression levels and lymph node status (p<0.05). These findings display an altered expression of many miRNAs in NPC tissues, thus providing information pertinent to pathophysiological and diagnostic research. Ultimately, miR-135b-5p and miR-205-5p may be implicated as novel NPC candidate biomarkers, while miR-93-5p, miR-650 and miR-183-5p may find application as relevant clinical pathology and diagnostic candidate biomarkers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1511-1515
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• 2014

Background and Aims: To explore the molecular mechanisms of miR-886-5p in breast cancer., we examined roles in inhibiting growth and migration of MCF-7 cells. Methods: MiR-886-5p mimics and inhibitors were used to express or inhibit MiR-886-5p, respectively, and MTT and clone formation assays were used to determine the survival and proliferation. Hoechst 33342/ PI double staining was applied to detect apoptosis. The expression of caspase-3, caspase-8, caspase-9, MT1-MMP, VEGF-C and VEGF-D was detected by Western blotting, and the levels of MMP2 and MMP9 secreted from MCF-7 cells were assessed by ELISA. MCF-7 cell migration was determined by wound healing and Transwell assays. Results: We found that the growth of MCF-7 cells was inhibited upon decreasing miR-886-5p levels. Inhibiting miR-866-5p also significantly induced apoptosis and decreased the migratory capacity of these cells. The expression of VEGF-C, VEGF-D, MT1-MMP, MMP2, and MMP9 was also found to be decreased as compared to controls. Conclusions: Our data show that downregulation of miR-886-5p expression in MCF-7 cells could significantly inhibit cell growth and migration. This might imply that inhibiting miR-886-5p could be a therapeutic strategy in breast cancer.